Puberty beginning earlier in boys

Researchers in the United States have found that signs of puberty are occurring in boys earlier than previously reported, news sources report.

The new averages are age 9 for blacks and 10 for whites and Hispanics, the Associated Press reported. The study was based off testes measurements in more than 4,000 boys as enlargement of testes is generally the earliest sign of puberty in boys, Health Day News reported. Some researchers claim early testes development may increase the risk for testicular cancer, but recent research found no such link.

Researchers have a few ideas as to why this phenomenon is being seen. Some suggest higher levels of obesity or inactivity to chemicals in food and water, each of which could disrupt normal hormone production, Health Day News reported.

Researchers say they are not necessarily viewing this as cause for concern. Other experts dispute that this trend is happening at all, the Associated Press reported.

This study used participants from 41 states via pediatricians; doctors asked parents and boys between ages 6 and 16 to take part during regular checkups between 2005 and 2010, the Associated Press reported.

Dr. Dianne Deplewski, a pediatric endocrinologist at the University of Chicago, said to the Associated Press that she has not seen any increase in the number of boys she sees for signs of early puberty.

"Just because this is happening doesn't mean this is normal or healthy," Deplewski said in the Associated Press.